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以黄腐酸为模型化合物,研究了臭氧氧化过程中有机物形态和结构的转化.采用超滤膜分级、GC/MS、电位滴定等手段考察了氧化中间产物的分子量分布、小分子有机物种类以及极性官能团的变化规律.结果表明,随着臭氧氧化反应的进行,有机物平均分子量显著降低;单位质量有机物(以DOC计)中极性官能团(羧基、酚羟基等)(mol/kgC)含量增加;同时伴随有十六酸、苯甲酸、十八醇等极性物质和丁二酸二(2-甲基丙)酯、直链烷烃等弱极性物质的生成.根据氧化过程中检测到的羟基自由基,提出黄腐酸的降解主要源于臭氧分子和羟基自由基的共同氧化作用;这两种具有不同反应机理的氧化剂对有机物的形态、结构与性质变化均有重要影响.
Fulvic acid was used as a model compound to study the conversion of organic forms and structures during ozonation.Using ultrafiltration membrane, GC / MS and potentiometric titration, the molecular weight distribution, the type of small molecule organic compounds, The results showed that with the progress of ozone oxidation, the average molecular weight of organic compounds decreased significantly. The contents of polar functional groups (carboxyl groups, phenolic hydroxyl groups, etc.) (Mol / kgC) increased with unit mass of organic compounds (DOC) Accompanied by polar substances such as palmitic acid, benzoic acid and octadecyl alcohol, and weak polar substances such as bis (2-methylpropyl) succinate and linear alkanes etc. According to the detected hydroxyl groups Free radicals. It is suggested that the degradation of fulvic acid is mainly caused by the co-oxidation of ozone molecules and hydroxyl radicals. These two oxidants with different reaction mechanisms have an important influence on the morphology, structure and properties of organic compounds.